At 300 K , the osmotic pressure of a decinormal solution of sodium chloride is 4.82 atm . The degree of dissociation of sodium chloride is $x \times 10^{-2}$. The value of $x$ is $\left(R=0.082 \mathrm{~L} \mathrm{~atm} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$

If 2 g of NaOH is dissolved to make 200 mL solution at $25^{\circ} \mathrm{C}$, the molarity ( $M$ ) at $90^{\circ} \mathrm{C}$ is

A solvent freezes at $17^{\circ} \mathrm{C}$ and its latent heat of fusion is $180 \mathrm{Jg}^{-1}$. The molal depression constant of the solvent is [units of $K_f=\mathrm{K} \mathrm{kg} \mathrm{mol}^{-1}$ ]